Stitching mechanism

ABSTRACT

A stitching mechanism mountable on the bed of an ordinary sewing machine in which a stitch frame is actuated two-dimensionally over a base plate having a window by a first endless string stringed doubly on pulleys mounted on said base plate and a second endless string stringed doubly on pulleys disposed so as to move with said first endless string and the movement of a tracing member connected to second endless string is transmitted to said stitch frame as a movement of the same magnitude but in the opposite direction.

United States Patent 1 1 1111 3,734,038

Taketomi 1451 May 22, 1973 541 STITCHING MECHANISM 2,837,046 6/1958 Carson et a1. ..112/121.12 3 451 366 6/1969 Beck ..l12/102 [76] Inventor: Bunsaku Taketomi, 56-141 Azalshikane Oazwlwasaki, Nisshim 3,528,378 9/1970 Westhofi ..1 12/121.1S Alchl-gun Alchl-ken Japan Primary Examiner-James R. Boler [22] Filed! Ju y 1971 Att0rneyWilliam C. Linton et a1.

21 A LN 165206 1 pp 0 57 ABSTRACT [30] Fmeign Application Priority Dam A stitching mechanism mountable on the bed of an ordinary sewing machine in which a stitch frame is actu- July 31, Japan ated two dimensionauy over a base plate having a window by a first endless string stringed doubly on pulleys [52] US. Cl ..l12/121.15, 112/102 mounted on said base plate and a second endless [51] [I'll- CI. ..D05b 21/00 String stringed doubly on P y di p so as to [58] Fleldlolfzsigliclllgu165"]65..l 12/ 11 l id move with said first endless string and the movement l 9 of a tracing member connected to second endless string is transmitted to said stitch frame as a move- [56] Reterences Cited ment of the same magnitude but in the opposite UNITED STATES PATENTS direction- 1,942,128 1/1934 Sommer ..112/121.15 7 Claims, 11 Drawing Figures PATENTEW- 3,734,038

arm 2 OF 3 PATENTED MAY 2 2 I973 SHEET 3 OF 3 FIGJO STITCHING MECHANISM BACKGROUND OF THE INVENTION This invention relates to a stitching mechanism mountable on an ordinary sewing machine for the purpose of stitching letters and patterns on a cloth. Conventionally it is practical to use a zigzag sewing machine with an exchangeable pattern cam or to move a stitch frame horizontally on a sewing machine bed according to a pattern cam. Consequently a number of pattern cams equal to the number of letters and patterns to be stitched are necessary. Also, a stitching operator cannot obtain the visual correspondence between the pattern cam and a corresponding pattern to be stitched on the cloth. Moreover, the operator can not modify the pattern to be stitched at will during a stitching operation. The range of the stitch frame movement or the needle bar of the zigzag sewing machine is limited within a considerably small area so long as a pattern cam of moderate size is used. In brief, the operator can not stitch letters or patterns freely as if he drew them with a pen.

SUMMARY OF THE INVENTION The above-mentioned defects of a means for stitching letters and patterns are eliminated by a stitching mechanism according to the present invention including a base plate mountable on a sewing machine bed, a first endless string stringed doubly on pulleys mounted rotatably on the base plate, a first supporting rod connected at right angles to the unidirectionally moving portion of the doubly stringed string, a second supporting rod connected at right angles to the oppositely moving portion of the doubly stringed string, a second endless string stringed doubly on pulleys mounted on the second supporting rod, a stitch frame disposed slideably on the first supporting rod, an arm connected at right angles to the unidirectionally moving portion of the second doubly stringed string and inserted slideably in a slot formed in the stitch frame perpendicularly to the first supporting rod and a tracing member attached to the oppositely moving portion of the second doubly stringed string. If the tracing member is displaced along model letters or patterns drawn on a model card, the stitch frame is moved by the same distance but in the opposite direction as the tracing member is. Thus, by tracing a model figure or drawing an arbitrary one with the tracing member, the operator can stitch the same letter or pattern as the model figure on a cloth fulled on the stitch frame watching both of the model figure and the stitched pattern. The maximum range of the movement of the stitch frame can be extended easily by providing a larger base plate. The letters or patterns stitched on the cloth are same as the model figures in size and disposition.

Having described the salient features of the present invention and the objects accomplished thereby it will be understood that the usage of the stitching mechanism according to the present invention makes the stitching operation of letters or patterns very easy without using any conventional pattern cam.

IN THE DRAWINGS FIG. 1 is a plane view of a stitching mechanism according to the present invention,

FIG. 2 is a perspective view of the stitching mechanism shown in FIG. 1 with some portion being broken away,

FIG. 3 is a brief plane view showing the relationship between model letters and stitched letters,

FIG. 4 is a plane view of another embodiment of the stitching mechanism (with some portion being broken away),

FIG. 5 is a perspective view of the stitching mechanism shown in FIG. 4,

FIG. 6 is a fragmental section taken on line 6--6 in FIG. 4,

FIG. 7 is a fragmental section taken on line 7-7 in FIG. 4,

FIG. 8 is a fragmental section taken on line 8-8 in FIG. 4,

FIG. 9 is a reduced perspective view of a transparent cover at the position shown on a imaginary line X in FIG. 4,

FIG. 10 is a reduced perspective view of a transparent cover mounted on the tracing base shown in FIG. 4, and

FIG. 11 is a partial view in the direction of Y-arrow in FIG. 5 showing a spacer fastened to a tracing base so as to keep a space to a base plate.

DETAILED DESCRIPTION OF THE INVENTION Referring FIGS. 1-3, a base plate 10 provided with a rectangular window 11 is mounted on a sewing machine bed 12 of an ordinary linear sewing machine by means of fastening screws 13. Six identical pulleys 14 are disposed rotatably on the base plate 10 around the rectangular window 11. Four of the pulleys 14 are placed pairwise near adjacent two corner portions of the base plate 10 and the other two are placed individually on the other two corner portions of the base plate 10. A first endless string 15 is stringed doubly on the pulleys 14. Thus the endless string 15 is U-shaped as a whole, A first supporting rod 16 is connected at right angles to the unidirectionally moving portions 15 of the first string 15. A second supporting rod 17 is connected at right angles to the oppositely moving portions 15" of the first endless string 15. Thus, the relative distance between the two parallel supporting rods is changed two times as much as the displacement of the string 15. On the first supporting rod 16, a rectangular stitch frame 18 (also known as an embroidery frame) provided with an inside frame 18" is mounted slideably by fitting a pair of hook portions 18' on the first supporting rod 16. The stitch frame 18 is provided with a slot 19 perpendicular to the first supporting rod 16. On the two end portions of the second supporting rod 17, a pair of pulleys 20 are disposed rotatably on which a second endless string 21 is stringed doubly. An arm 22 is connected to the unidirectionally moving portion 21 of the second endless string 21 and the bent free end portion of the arm 22 is slideably inserted in the slot 19. A tracing member 23 with an integral tracing pen holder 23' is secured to the oppositely moving portion 21" of the second endless string 21 by means of a small screw 24. The tracing member 23 is provided with a pair of bearing portions 23" in which the second sup porting rod 17 is inserted. Thus, when the tracing member 23 is displaced in a direction parallel to the rod 17 by a certain distance, the stitch frame 18 is displaced in the opposite direction by the same distance. When the tracing member 23 is displaced in a direction perpendicular to the rod 17 by a certain distance, the stitch frame 18 is displaced also in the opposite direction by the same distance. A tracing pen 25 is inserted in a pen hole bored through the tracing pen holder 23'. A pair of guiding plates 26 are secured on the base plate perpendicularly to the rods 16 and 17 so as to guide the ends of the rods 16 and 17. The gap between the end of the rod 16 or 17 and the guiding plate 26 is preferably as thin as possible because, if otherwise, the displacement of the tracing member 23 is transmitted distortedly to the stitch frame 18 on account of the longitudinal movement of the rod 16 or 17.

In operating the stitching mechanism above described, a stitching operator moves the tracing member 23 and bring the stitch frame 18 under the needle 27 of the ordinary sewing machine. Then, the operator puts a model figure card 28 near the tracing pen 25 and traces a model figure 28' with the tracing pen 25. The stitch frame 18 is actuated by the first supporting rod 16 and the arm 22 and the resultant displacement of the stitch frame 18 is of the same magnitude as that of the tracing pen 25 but in the opposite direction. When the needle 27 is actuated to reciprocate vertically, a reproduced figure 28" quite same as the model figure 28 is stitched on the cloth 29. The operator can obtain the visual correspondence between the model figure 28 and the reproduced figure 28" operating the tracing pen 25. The operator may draw any letter or pattern with the tracing pen without tracing the model figure 28.

Referring to FIGS. 4-10, another embodiment is described. Members substantially same as those in the previous embodiment are given the same references and the description thereof is omitted. One of the pulleys 14 is inserted in an elongated hole 30 and is fixed at a suitable position. The tention of the first endless string is, thus, adjustable. The base plate 10 is'provided with an extending portion 10 with an opening and another extending portion 10" with a cut 31. The base plate 10 is secured on the sewing machine bed 12 by means of fastening screws 13. However, the base plate 10 can be turned around the fastening screw 13 inserted in the extending portion 10' by loosing both screws when the base plate 10 is obstructive to an operation such as exchanging threads. The first supporting rod 16 as well as the second supporting rod 17 is provided with a pair of grooved rollers 32 which are rollably placed on a pair of guiding plates 26. The rod 16 is connected to and actuated by the first string 15 similarly as in the case of the previous embodiment but the weight of the rods 16 and 17 is beared by the guiding plates 26. The second supporting rod 17 is inserted rotatably in a pair of bearing portions 33 of an arm base 33 which is movably placed on the base plate 10. A pair of pulleys are mounted rotatably on the tracing base 34 and the second supporting rod 17 is rotatably inserted in a pair of bearing portions 34' formed as part of the tracing base 34 which is connected at right angles to and actuated by the oppositely moving portion 15" of the first endless string 15. On the pulleys 20, the second endless string 21 is stringed doubly in parallel with the second supporting rod 17. The arm base 33 is connected to the unidirectionally moving portion 21' of the endless string 21 and is provided with an integral arm 35 the bent end portion of which is extending through the slot 19 from the lower side of the stitch frame 18. The tracing base 34 is provided with a tracing slot 36 parallel to the second supporting rod 17. In the tracing slot 36 is slideably fit a tracing pen holder 37 with an opening in which the tracing pen 25 is inserted. The tracing pen holder 37 is connected to the oppositely moving portion 21" of the second endless string 21 whereby the arm 35, therefore, the stitch frame 18 is displaced along the rod 16 by the same distance but in the opposite direction as the tracing pen holder 25 is. The way in which a reproduced figure is stitched on a cloth fulled on the stitch frame 18 is similar'to that in the previous embodiment. However, the movement of the tracing pen 25 is transmitted to the stitch frame 18 less distortedly with the present embodiment, because the transverse displacement of the strings 15 and 21 are prevented by the engagements between the tracing slot 36 and the tracing pen holder 37 and between the grooved rollers 32 and the guiding plates 26. A transparent cover 38 is preferably attached to the base plate 10. A transparent cover 39 is set up over the right and left pulleys 20, and the both ends 39' of the cover 39 is fastened on the tracing base 34 by means of the screws 39".

As is understood from the foregoing description, the stitching operator can stitch any figure on the cloth fulled on the stitch frame by tracing the corresponding model figure with the tracing pen as if he drew letters or patterns. Any pattern cams used conventionally is, no longer, necessary but instead only mode] figure cards are necessary on which model figures are printed beforehand. Moreover, these model figure cards are even unnecessary when the operator draw his original figures with the tracing pen. During the stitching operation, the modification of a figure to be stitched and the exchange of the model figure cards is at the will of the operator. The area where stitching is possible is extended without difficulty by providing a larger base plate.

Although the present invention has been described with preferred embodiments, it should be understood that many changes and modifications are possible without departing from the spirits of the present invention and the scope of the accompanying claims.

What I claim is:

1. A stitching mechanism mountable on the bed of an ordinary sewing machine, including a base plate provided with a window, said base plate being mountable on said bed, plural pulleys mounted rotatably on said base plate at positions surrounding said window, a first endless string stringed doubly on said pulleys, a first supporting rod connected at right angles to the unidirectionally moving portion of said first endless string, a second supporting rod connected at right angles to the oppositely moving portion of said first endless string, a stitch frame mounted slideably on said first supporting rod, said stitch frame being provided with a slot perpendicular to said first supporting rod, a pair of pulleys mounted rotatably on said second supporting rod, a second endless string stringed doubly on said pulleys on the second supporting rod, an arm connected to the unidirectionally moving portion of said second endless string, the free end of said arm being inserted slideably in said slot and a tracing member with a tracing pen holder and bearing portions, the second supporting rod being inserted in said bearing portions whereby said tracing member can slide along said second supporting rod.

2. A stitching mechanism as described in claim 1 including a transparent cover fit detachably to said base plate.

3. A stitching mechanism as described in claim 1, including a pair of guiding plate secured on said base plate near both ends of said first and second supporting rods whereby the longitudinal movement of said rods can be prevented.

4. A stitching mechanism mountable on the bed of an ordinary sewing machine, including a base plate provided with a window, said base plate being mountable on said bed, plural pulleys mounted rotatably on said base plate at positions surrounding said window, a first endless string stringed doubly. on said pulleys, a first supporting rod connected at right angles to the unidirectionally moving portion of said first endless string, a pair of grooved rollers attached to both ends of said first supporting rod, a pair of guiding plates disposed on the opposite side portions of said base plate, said grooved rollers being put rollably on said guiding plates, a stitch frame mounted slideably on said first supporting rod, said stitch frame being provided with a slot perpendicular to said first supporting rod, a tracing base provided with integral bearing portions and tracing slot formed longitudinally, said tracing base being connected at right angles to the oppositely moving portion of said first endless string whereby said tracing slot can be parallel to said first supporting rod, a second supporting rod provided with a pair of grooved rollers at both ends, said grooved rollers being mounted slideably on said guiding plates, a pair of pulleys mounted rotatably on said tracing base, a second endless string stringed doubly on said pulleys of said tracing base in the direction parallel to said tracing slot, an arm base having a pair of bearing portions in which said second supporting rod being inserted for the slideable movement of said arm base, said arm base being connected to the unidirectionally movin'g portion of said second endless string, an arm secured on said arm base, the free end of said arm being fit slideably in said slot of said stitch frame and a tracing pen holder connected to the oppositely moving portion of said second endless string, said tracing pen holder being fit slideably in said tracing slot.

5. A stitching mechanism as described in claim 4 in which said base plate is provided with an elongated hole for positioning adjustably one of said fastening screws whereby the tension of said first endless string can be adjusted.

6. A stitching mechanism as described in claim 4, in which said base plate is provided with a cut at its one side for inserting one of said fastening screws.

'7. A stitching mechanism as described in claim 4, including a transparent cover mounted detachably on said base plate. 

1. A stitching mechanism mountable on the bed of an ordinary sewing machine, including a base plate provided with a window, said base plate being mountable on said bed, plural pulleys mounted rotatably on said base plate at positions surrounding said window, a first endless string stringed doubly on said pulleys, a first supporting rod connected at right angles to the unidirectionally moving portion of said first endless string, a second supporting rod connected at right angles to the oppositely moving portion of said first endless string, a stitch frame mounted slideably on said first supporting rod, said stitch frame being provided with a slot perpendicular to said first supporting rod, a pair of pulleys mounted rotatably on said second supporting rod, a second endless string stringed doubly on said pulleys on the second supporting rod, an arm connected to the unidirectionally moving portion of said second endless string, the free end of said arm being inserted slideably in said slot and a tracing member with a tracing pen holder and bearing portions, the second supporting rod being inserted in said bearing portions whereby said tracing member can slide along said second supporting rod.
 2. A stitching mechanism as described in claim 1 including a transparent cover fit detachably to said base plate.
 3. A stitching mechanism as described in claim 1, including a pair of guiding plate secured on said base plate near both ends of said first and second supporting rods whereby the longitudinal movement of said rods can be prevented.
 4. A stitching mechanism mountable on the bed of an ordinary sewing machine, including a base plate provided with a window, said base plate being mountable on said bed, plural pulleys mounted rotatably on said base plate at positions surrounding said window, a first endless string stringed doubly on said pulleys, a first supporting rod connected at right angles to the unidirectionally moving portion of said first endless string, a pair of grooved rollers attached to both ends of said first supporting rod, a pair of guiding plates disposed on the opposite side portions of said base plate, said grooved rollers being put rollably on said guiding plates, a stitch frame mounted slideably on said first supporting rod, said stitch frame being provided with a slot perpendicular to said first supporting rod, a tracing base provided with integral bearing portions and tracing slot formed longitudinally, said tracing base being connected at right angles to the oppositely moving portion of said first endless string whereby said tracing slot can be parallel to said first supporting rod, a second supporting rod provided with a Pair of grooved rollers at both ends, said grooved rollers being mounted slideably on said guiding plates, a pair of pulleys mounted rotatably on said tracing base, a second endless string stringed doubly on said pulleys of said tracing base in the direction parallel to said tracing slot, an arm base having a pair of bearing portions in which said second supporting rod being inserted for the slideable movement of said arm base, said arm base being connected to the unidirectionally moving portion of said second endless string, an arm secured on said arm base, the free end of said arm being fit slideably in said slot of said stitch frame and a tracing pen holder connected to the oppositely moving portion of said second endless string, said tracing pen holder being fit slideably in said tracing slot.
 5. A stitching mechanism as described in claim 4 in which said base plate is provided with an elongated hole for positioning adjustably one of said fastening screws whereby the tension of said first endless string can be adjusted.
 6. A stitching mechanism as described in claim 4, in which said base plate is provided with a cut at its one side for inserting one of said fastening screws.
 7. A stitching mechanism as described in claim 4, including a transparent cover mounted detachably on said base plate. 